W256 Cypress Semiconductor Corp., W256 Datasheet
W256
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W256 Summary of contents
Page 1
... SDRAM DIMMs and 2 DDR DIMMs. The W256 can be used in conjunction with the W250-02 or similar clock syn- thesizer for the VIA Pro 266 chipset. The W256 also includes an SMBus interface which can enable or disable each output clock. On power-up, all output clocks are enabled (internal pull up). ...
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... Clock outputs. These outputs provide complementary copies of BUF_IN when SEL_DDR is active. These outputs provide copies of BUF_IN when SEL_DDR is inactive. Voltage swing depends on VDD3.3_2.5 pow- er supply. Connect to 2.5V power supply when W256 is configured for DDR-ONLY mode. Connect to 3.3V power supply, when W256 is configured for stan- dard SDRAM mode. Ground 2 W256 ...
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... The Serial bits will be read by the clock driver in the following order: Byte 0 - Bits Byte 1 - Bits Byte N - Bits • Reserved and unused bits should be programmed to “0”. • SMBus Address for the W256 is ...
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... See Test Circuity (Refer to Figure 1) 4 Min. Typ. Max. 3.135 3.465 2.375 2.625 Min. Typ. Max. 0.8 2 -18 - 0.6 1.7 400 500 100 0.7 VDD +0.6 (VDD/2) VDD/2 (VDD/2) -0.1 +0 W256 Unit V V ° Unit ...
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... Measured between 20% to 80% of output (Refer to Figure 1) Measured between 20% to 80% of output (Refer to Figure 1) All outputs equally loaded [2] Input edge greater than 1 V/ns [2] Input edge greater than 1 V/ns [2] Input edge greater than 1 V/ns 3.3V 0. W256 Min. Typ. Max. Unit 66 133 MHz –5% +5% 1.0 2.50 V/ns 1 ...
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... Figure 1 shows the differential clock directly terminated by a 120 VCC VCC Device Out Under Test Out Figure 1. Differential Signal Using Direct Termination Resistor. Ordering Information Ordering Code W256 Document #: 38-01083-*A Preliminary Package Type 28-pin SSOP 6 W256 resistor VTR R =120 T Receiver VCP Operating Range Commercial ...
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... All bypass caps = 0.1 F ceramic Preliminary FB VDD 10 F 0.005 .005 µF V =VIA to respective supply plane layer 7 W256 ...
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... The inclusion of Cypress Semiconductor products in life-support systems application implies that the manufacturer assumes all risk of such use and in doing so indemnifies Cypress Semiconductor against all charges. Preliminary W256 ...